Blading construction for turbo-compressor impellers.



O. BANNER. BLADING CONSTRUCTION FOR TURBO COMPRESSOR IMPELLERS.APPLICATION IILED'0GT.25, 1912.

1,071,660. Patented Aug. 26, 1913.

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OTTO BAN-NEE, OF EASTON, PENLISYLVANIA, ASSIGNOB TO INGERSOIIL-RANI)COM- PANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Aug. 26,1913.

Application filed October 25, 1912. Serial No. 727,651.

To all whom it may concern Be it known that I, OTTO BANNER, a subject ofthe German Emperor, residing at Easton, in the county of Northampton andState of Pennsylvania, have inventeda certain new and useful Improvementin Blading Construction for Turbo- Compressor Impellers, of which thefollowing is a specification.

This invention relates to turbo compressor impellers and moreparticularly to the blading of such impellers. v

In the construction of turbo compressor impellers a common formof'blading is that which consists of a piece of sheet. metal the edgesof which are bent over at right angles to form flanges which are pivotedto the disk and cover of the impeller. In practice it has been foundhowever that the great centrifugal strain causes such blades to give waynear the edges at their outer ehds with the result that semicircularpieces" are detachcd bodily from the ends of the blades impairing theefliciency' of the impeller and throwin it out of balance.

The object of the present, invention is to prevent such breaking of theblades and this is accomplished, broadly speaking, by making the bladesin two parts, the inner por tion. where there is comparatively littlestrain being made of the usual bent sheet' material and the outer partof a separate piece of stronger material which is usually incapable ofbeing bent and must be milled into shape, a process which if applied tothe whole blade would make the cost prohibitive.

Practical embodiments of this idea are shown in the accompanyingdrawings in which,

Figure 1 shows a section of an impeller embodying my blading with thecover partly broken away, Fig. 2 shows a section on the line 11-'11 ofFig. 1, and Figs. 3-6 show modified formsofthe blading.

The impeller as shown in Figs. 1 and 2 comprises a disk'l and cover 2.Between these are secured the blades which consist of inner portions 3made of sheet metal with flanges 4 bent at right angles and secured tothe disk and cover by rivets 5, and outer portions 6 made somewhat inthe shape of an I beam with flanges 7 and 8 secured to the disk andc'vei' by rivets 9. This outer portion of the b ade is preferably made()1 a outer portion 6 is made of a heavier and 13 secured to the diskand cover by rivets strongsteel which can not be bent and hence must bemilled into shape. Thexcenter of the blade at the end is made thinner tolessen the centrifugal stress on the blade which' makes itself felt moststrongly on each side of the blade close to the disk.

In 'Fig. 3 a form is shown wherein thepiece passing through it. In thisform the inner end of the part 6 is riveted to the outer end of theinner part 3. In Fig. 4 a similar form is shown wherein the part 6 hasflan es to secure it to the disk and cover and is a so riveted to theouter end of the part 3. i

In Figs. 5 and 6 a form is shown similar to Fig. l but provided with lon'it-udinal strengthening ribs 10 extending along one face of the blade.

It is to be understood that the present' showing and descriptiondiscloses only cer tain specified modifications of my invention andother forms and modifications are included in the spirit and scope ofthe invention as expressed in the claims.

What. I claim is: 4

1. In a turbo compressor, a disk, a cover, and blades between said diskand cover said blades comprising an inner part secured to said disk andcover and a separate outer v part having flanges thereon secured to'said .85 disk and cover.

2. In a turbo'compressor, a disk, a cover and blades between said diskand cover, s'ai'd blades comprising an inner part secured to. said diskand cover andan outer part Sc cured to said disk and coverformingacontinuation of the innerpart, said outerpa rt" being of strongermaterial than said inner p 3. Int; turbo compressor, a disk, a cover,and blades between said disk and cover, said blades comprising an innerpart having bent" flanges secured to said disk and cover and an outerpart secured to said disk and'cov'er' forming a continuation of theinner part, -10Q said outer part being of stronger material than saidinner part,

4. In a turbo compressor, a disk, a cover, and blades between said diskand cover, said blades each comprising an inner part having. 1,0 5 bentflanges secured to said disk and cover and an outer part having flangessecured to the disk and cover. said outer part forming bent flangessecured to said disk and cover I =Witnesses:

a continuation (if the inner part and being said outer part forming acontinuation of 1 of. an unbendable material strbnger than the innerpart and being of an unbendable said inner part; material stronger thansaid inner part.

5, In a turbo compresspr a disk, a cover, In testimony whereofiI havehereunto set and blades between said disi; andcover, said my hand.

' OTTO BANNER.

blades each comprising an mner part having and an outer part-havingflanges. seured to PAUL HOFFMAN;

the disk'and eover, and longitudinal ribs, F. A. POPE.

